Method of die casting heads on pins



Dec. 16, 1941. 1.. H. MORIN ETAL 2,266,432

METHOD OF DIE CASTING HEADS ON PINS Filed Feb. 28, 1939 INVENTORzmwwmew/wwxr dd/J HMO/Pl ATTORNEY Patented Dec. 16, 1941 METHOD OF DIECASTING HEADS ON PINS Louis B. Morin and Davis Marinsky, Bronx, N. Y.,assignors to Whitehall Patents Corporation, Bronx, N. Y., a corporationor New York Application February 28, 1939, Serial No. 258,928

9 Claims.

This invention relates to the method of die casting heads or bodies uponpins and like members, and more particularly to a method wherein aseries of successive pins are arranged upon an elongated supportingstrip or tape and fed thereby into position between relatively movabledies to expose a portion 01' the pin within the impression or moldcavity of the dies and in pressure feeding heated casting material intothe impression to form on that part of the pin arranged therein, thehead or other body; and then in trimming the casting just formed toproduce a finished casting on the pins successively moved into castingposition. The invention further relates to the method of forming headsor bodies of two differently colored thermoplastic materials upon thepins. The novel steps of the I method will be best understood from thefollowing description when taken together with the accompanying drawingin which certain embodiments of the invention are diagrammaticallydisclosed, and in which the separate parts are designated by suitablereference characters in each of the views. and in which:

Fig. 1 is a diagrammatic view illustrating a part of a pin supportingstrip and showing the method of bringing successive pins on the strip inregistering position between relatively movable dies in forming heads onsaid pins.

Fig. 2 is a sectional view substantially on the line 2-2 of Fig. 1.

Fig. 3 is an enlarged diagrammatic view substantially similar to thatshown in Fig. 1, but omitting parts 01' the construction and showinganother adaptation of the invention.

Fig. 4 is a view showing several difierent types of heads and pinconstructions.

Fig. 5 is a perspective view of a modified form of part 01' a completehead made according to the method shown in Fig. 3; and, Fig. 6 is a viewsimilar to Fig. 5 showing the completion of the head.

Figs. 1 and 2 of the drawing show one adaptation of the invention and inthese figures a diagrammatic illustration is shown of the method offorming a single unitary die cast body, for example, a head upon a pin,rod or other mounting member. In carrying this method into effect, anelongated flexible strip l of paper or any other suitable material isprovided and to this strip or conveyor member is -attached at regularlyspaced intervals a series of pins or other mountings ll, one end of thepins being enlarged or provided with anchor portions I2; whereas theother end II is pointed. The member transversely spaced keepers It forsupporting the pins in connection therewith. At [5 is shown relativelymovable dies of a die casting machine, adjacent surfaces of the diesbeing recessed to form a mold cavity or impression it of any desiredform or contour, so long as the contour will permit ejection of theresulting cast body or head 11 formed by the injection of heated castingmaterial into the impression I! through a gate or admission orifice lBaon the parting line it of the dies. The material is injected through anozzle l9, indicated in Fig. 1 oi. the drawing, which will be timelymoved into registering position with the gate orifice lid; and in likemanner, a timely pressure discharge of the casting material will beforced from the nozzle into the impression l8.

It is also desirable in some instances to arrange a pin 20 on theparting line of the dies so as to enter the gate passage I to facilitateejection of the casting from the dies I5 in the separation thereof.However, in some instances, the pins It! will be of sumcient strengthand suitably supported to serve for this purpose.

At this time it is also pointed out that in some instances the shape orcontour of the orifice |6a will be such that the resulting gate 2|trimmed from the body I! by a knife or other trimming tool 22 will be ofa contour to form another article. For example, a button may be soformed. This is, of course, by no means essential. However, in forminganother article, the core 20 serves as the means to control the shapingthereof.

Suitable means such as guide shoes or channels 23, 24, will be employedto guide the pins Ii, into and between the dies l5 so as to bring theenlarged ends l2 in proper registering position with the impression it.It will also be apparent that suitable means will be provided to guidethe mounting strip or tape ID from a roll Illa, note Fig. 2, intoposition to pass between the guides 23. .The pin 20 may be used as thefeeding and spacing means, it being understood that after one casting isformed, it is fed by the pin into a position adjacent the lower surfaceoi! the dies when the dies are in a fully open position, after which thedies are partially closed and the casting is stripped from the pin,leaving the casting supported upon .the lower surface of the dies. Thisspacing between the cast position and the position upon the lowersurface of the dies represents equal spacing of the pin II as willreadily appear. When the ejector and feed pin 20 is it is provided withnot employed, other means will be provided controlling the feed of thetape Hi to bring successive pins in proper registering alinement withthe impression.

It will, of course, be apparent that the pins II are movable verticallybetween the adjacent surfaces of the dies when in open position andnormally moved on the parting line of said dies. It will be apparentthat the strip or tape Ill may constitute a permanent part of theresulting product; that is to say, the pin with the die cast headsthereon may be sold in the'strip form of any given length or with anydesired number of pins on a strip or sheet, depending entirely upon themanner of selling or using the same. The die cast heads may be formedfrom any suitable die cast material including the various metals ormetal alloys as well as thermoplastic materials, such for example ascellulose acetate. In,the latter instance, a dual nozzle constructionmay be employed, such as diagrammatically illustrated in Fig. 3 of thedrawing, with the nozzles arranged horizontally rather than verticallyso that each nozzle may be moved into registering alinement with thegate l6a in forming any desired series of difierent coloredthermoplastic castings on the pins, To give one illustration of the manypossible arrangements of two color castings, it will appear that everytwo successive castings may be in one color and the next successive one,two, or any other number of castings, may be another color. Thisoperation is repeated throughout the continuous operation of formingintermittently the successive series of castings at a relatively highspeed.

Considering Fig. 4 of the drawing it will appear' that any desired shapeor form of casting may be arranged upon the pins. For example at Ila isshown the pin having a square head 11a.

At ilb is shown a pin having a disc-type head iib; whereas at Me isshown a pin having an offset l2 instead of the enlargement l2 shown inFig. 1 with a spherical head He arranged thereon. Here it must bepointed out that the illustrations are merely suggestions of the manytypes of heads or enlarged bodies that can be formed upon th'e pins orother mounting members. In view of the fact that very flne definitionscan be produced in pressure die castings oi the type and kind underconsideration, the heads may be engraved or characterized in any mannerwhich will enable the castings ejected from the dies which are employed.

In Fig. 3 of the drawing, another adaptation of the invention is shownwhich is applicable primari y to the casting of thermoplastic materials,such for example as cellulose acetate; and in this figure isdiagrammatically illustrated at Ifla a part of a pin conveying or feedtape or member similar to the member l6, upon which pins ild similar tothe pins H are arranged and guided in the same manner between relativelymovable dies 25. The dies are provided on adjacent surfaces thereof withtwo independent impressions 26 and 21, which are spaced apart a distanceequal to the spacing of the pins ild, the impression 26 having a gateorifice 28 leading thereto on the parting line of the die; whereas theimpression 21 has a gate orifice 29 leading thereto. The orifice 28enters the impression 26 at the lower edge of the impression as picturedin Fig. 3; whereas the orifice 29 enters the impression 21 centrally ofthe outer edge thereof so that when the part casting 30 is moved fromthe impression 26 into the impression 21, the gate portion 30a of saidpart casting will be arranged in an auxiliary orifice 28a and bluecasting material 34, in the illustration given, into the impressions 26,21. The cast body 30 will be cast in a red thermoplastic material andwill have a dovetail key member 35 on the outer surface thereof; whereasthe cast body 36 of the blue thermoplastic material will be formedaround the dovetail coupling 35 in the impression 21, so that theresulting head will be composed of the two cast bodies 30, 36, the body36 having a gate 36a. The gates 39a, 36a are trimmed on by angularlyarranged and operating knifes or trimming tools 31, 38, when thecomplete casting is disposed upon the lower surface 25a of the dies, asseen in Fig. 3 of the drawing. This surface is so spaced with respect tothe impression 21 as to be equal to the spacing of the pins lid. Inother words, when an ejector pin 39, on which the gates 39a, 3612 areformed, is moved downwardly, the gate 30a will be moved into registeringposition with the passage 28a, and the gate 36a will be moved intoposition to engage the surface 25a as seen in the drawing.

It will be understood that the pin 39 is stripped from the gates 30a,36a, and returned to its raised position intermediate successive castingoperations and while the dies are in a partly open position. Here again.it will be understood that in some instances, the feed and ejector pin39 need not be employed, and the pins Hd may be used for this purpose aswell as to properly feed the castings through the stages of successiveoperations.

It is believed that the method disclosed in Fig. 3 will be quite clearfrom the foregoing description. However, it will be understood that thecycle of operation is as iollows: A pin l Id is first moved to disposethe enlarged portion at one end thereof within the impression 26; itbeing understood that in the initial operation means will be provided toplug a pin receiving aperture opening into the impression 31. In thefirst injeotionof heated thermoplastic material, a casting, such as 30,including the dovetail key element 35, will be formed in the impression26. The pin with this partially formed head is then moved into theimpression 21 which is shaped to receive the head operation, the firstcompletely formed casting is moved into position adjacent the lowersurface 25a of the dies, and when in this position, and in performingthe next casting operation, the gates 30a, 36a, are trimmed off by theknives 31, 38. The angular arrangement of these knives is to clear thecastings to permit the same to feed into a suitable receiver arrangedbelow the dies.

In Figs. 5 and 6 of the drawing is shown one of many adaptations of themethod as disclosed in Fig. 3, for example in making a first casting 40,equivalent to the casting 30, instead of forming a dovetail member 35, amember 4| in the form of a letter T will be cast so that when the secondcast body 62 equivalent to the body 36 is formed,

the T will be disposed through the front surface of the cast body 42. Inthis arrangement it will, of course, be apparent that the gate orifice29 will be spaced so as to clear the surface of the T. There is noapparent need of attempting to mention the many possible adaptations ofthe method shown in Fig. 3, which not only consists in the casting ofheads or enlarged bodies of two different colors, butalso in the manydifferent possible shapings of the bodies formed by different coloredcast materials.

With thermoplastic materials of the type and kind under consideration,it is also possible to mix or blend two or more different coloredmaterials in each of the cylinders Ma, Ma, leading to the dischargenozzles. Thus each body or cast portion of the resulting unitary castingmay not only be of different colors, but of different combinations ofmulti-colors, or multi-colors in one cast portion and a solid color inthe other cast portion.

It will, of course, be understood that the various casting materialsemployed are heated and discharged in accordance with processes whichare now well known in the art. Therefore, no specific mention need herebe made.

It will also be apparent that the invention as herein illustrated hasbeen associated with pins, but the invention is applicable to the diecasting of bodies of single or two color casting materials upon mountingmembers of any type or kind, intermittently moved into position withinthe impression'or mold cavity of relatively movable dies, and in theprovision of means for feeding and guiding said members with respect tothe dies. It will also be understood that in some instances the pinsneed not necessarily be mounting members, but merely other forms of corepinsnipon which the individually cast parts are formed in the mannertaught in Fig. 3 of the drawing, this being the case Where it is desiredsimply to produce unitary cast bodies composed of the cast parts. Infact, the same principle may be applied to the teachings in Figs. 1 and2 of the drawing. In both instances, the other core pins need notnecessarily be employed.

Having fully described our invention, what we claim as new and desire tosecure by Letters Patent, is:

l. The herein described method of forming die cast bodies on one end ofan elongated member, which consists in first die casting one body onsaid end of the member with an anchor or keying portion on one surfaceof said body, then die casting another body of different characteristicson the first named body to engage the keying portion thereof to form onthe resulting member an enlarged head composed of both of said castbodies.

2. The herein described method of forming die cast bodies on one end ofan elongated member, which consists in first die casting one body onsaid end of the member with an anchor or keying portion on one surfaceof said body, then die cast" ing another body of differentcharacteristics on the first named body to engage the keying portionthereof to form on the resulting member an enlarged head composed ofboth of said cast bodies, and so casting one of said bodies as to exposea part thereof through an outer surface of the other of said bodies.

ing portion on one surface of said body, then die casting another bodyof different characteristics on the first named body to engage thekeying portion thereof to form on the resulting member an enlarged headcomposed of both of said cast bodies, and forming the two cast bodiessimultaneously in successive die casting operations upon independentmembers by the simultaneous pressure injection of casting material intoindepend ent impressions of relatively-movable dies.

4. The herein described method of forming two die cast bodies upon amounting member which consists in moving toward and from each other dieshaving pairs of spaced impressions upon adjacent surfaces thereof, onepair of impressions defining a small mold chamber and gate passage, theother pair of impressions defining a larger mold chamber and a secondgate passage, and at least part of said large mold chamber having thesame configuration as part of said first named chamber and passage,moving successive members relatively to the dies along the parting linethereof to bring each member into registering position with eachimpression, closing the dies around parts of said members, and injectingheated casting material simultaneously from two sources of supply intothe separate impressions of the closed dies to form individual castbodies therein and upon said independent members extending into eachimpression.

5. The herein described method of forming two die cast bodies upon amounting member which consists in moving toward and from each other dieshaving pairs of spaced impressions upon adjacent surfaces thereof, onepair of impressions defining a small mold chamber and gate passage, theother pair of impressions defining a' larger mold chamber and a secondgate passage, and at least part of said large mold chamber having thesame configuration as part of said first named chamber and passage,moving successive members relatively to the dies along the parting linethereof to bring each member into registering position with eachimpression, closing the dies around parts of said members, injectingheated casting material simultaneously from two sources of supply intothe separate impressions of the closed dies to form individual castbodies therein and upon said independent members extending into eachimpression, and moving the members by means of a movable core extendingthrough said first named gate passage and into said second named gatepassage.

6. The herein described method of forming two die cast bodies upon amounting member which consists in moving toward and from each other dieshaving pairs of spaced impressions upon adjacent surfaces thereof, onepair of impressions defining a small mold chamber and gate passage, theother pair of impressions defining a larger mold chamber and a secondgate passage, and at least part of said large mold chamber having thesame configuration as part of said first named chamber and passage,moving successive members relatively to the dies along the parting linethereof to bring each member into registering position with eachimpression, closing the diesaround parts of said members, and injectingheated casting material simultaneously from two sources of supply into3. The herein described method of forming div "the separate impressionsof the closed dies to cast bodies on one end of an elongated member,which consists in first die casting one body on 'form individual castbodies therein and upon said independent members extending into eachsaid end of the member with an anchor or key impression. Supporting eachdual cast y 011 its mounting member outwardly of the dies and trimmingthe gates therefrom during the casting of the next successive bodies.

'7. The herein described method of formin a series of similar multiplecolored thermoplastic die cast bodies on end portions of elongatedmembers, which-comprises moving dies having pairs of impressions formingspaced mold chambers and gate passages therein toward and from eachother, arranging elongated members so that part of successive membersextend into adjacent mold chambers, intermittently moving said members adistance equal to the spacing between said members to position the partsthereof in the mold chambers when the dies are closed, and

, simultaneously injecting different colored casting materials throughsaid gate passages to form a casting in the first mold chamber directlyupon the member arranged therein, and to form in the next adjacent moldchamber a casting arranged upon the previously formed casting from saidfirst named chamber.

8. The herein described method of forming two die cast bodies upon amounting member which consists in moving toward and from each other dieshaving pairs of spaced impressions upon adjacent surfaces thereof, onepair of impressions defining a small mold chamber and gate passage, theother pair of impressions defining a large mold chamber and a secondgate passage, and at least part of said large mold chamber having thesame configuration as part of said first named chamber and passage,moving successive members relatively to the (lies along the parting linethereof to bring each member into registering position with eachimpression, closing the dies around parts of said members, injectingheated casting material simultaneously from two sources of supply intothe separate impressions of the closed dies to form individual castbodies therein and upon said independent members extending into. eachimpression, providing for proper spacing of said members by attachingthe same to an elongated support and conveyor and intermittently feedingthe conveyor between successive casting operations to continuously feedsaid members relatively to said dies.

9. The herein described method of forming multiple colored thermoplasticdie cast bodies which consists in moving toward and from each other dieshaving pairs of impressions in abutting surfaces thereof forming spacedmold chambers and gate passages, passing a mounting member havingequally spaced projecting parts relatively to said dies to dispose saidspaced parts thereof within said mold chambers, simultaneously injectingdiflerent colored casting materials into said mold chambers to form acasting in one mold chamber directly upon one of said parts and acasting in the adjacent mold chamber arranged upon an adjacent partincluding a previously formed casting from said first named chamber,intermittently feeding said mounting member and castings through adistance equal to the spacing of said chambers and projecting parts bymeans of a movable core pin passing through the gate passage of saidfirst named chamber and extending into the gate passage of the secondnamed chamber, supporting each dual-cast body against a recessed outersurface of the dies during the casting of next successive bodies, andtrimming the gate portions from said dual body while supported in saidposition.

LOUIS H. MORIN. DAVIS MARINSKY.

